inclusion criteria: age of 18 through 60 years at screening. covid-19 negative using rapid antigen test at screening able and willing to provide written informed consent to take part in the study. able and willing to provide adequate information for locator purposes. availability to return for all study visits, barring unforeseen circumstances. agree not to participate in other research studies involving drugs and/or medical devices during the study period. female participants must meet the following criteria: postmenopausal or using (or willing to use) an acceptable form of contraception (e.g., barrier method, iud, hormonal contraception, sexual abstinence, surgical sterilization, or vasectomization of male partner). if the female participant has female partners only, the method of contraception will be noted as a barrier method in the study documentation. not be pregnant at the baseline or enrollment visit not be breastfeeding at screening or intend to breastfeed during study participation per participant report willingness and ability to safely defer vaccinations until after study participation is completed. must be in general good health in the opinion of the investigator.

inclusion criteria: age of 18 through 60 years at screening. covid-19 negative using rapid antigen test at screening able and willing to provide written informed consent to take part in the study. able and willing to provide adequate information for locator purposes. availability to return for all study visits, barring unforeseen circumstances. agree not to participate in other research studies involving drugs and/or medical devices during the study period. female participants must meet the following criteria: postmenopausal or using (or willing to use) an acceptable form of contraception (e.g., barrier method, iud, hormonal contraception, sexual abstinence, surgical sterilization, or vasectomization of male partner). if the female participant has female partners only, the method of contraception will be noted as a barrier method in the study documentation. not be pregnant at the baseline or enrollment visit not be breastfeeding at screening or intend to breastfeed during study participation per participant report willingness and ability to safely defer vaccinations until after study participation is completed. must be in general good health in the opinion of the investigator.